Safety-collar for abrasive-wheels.



PATENTED JAN. 7, 1908.

D. B. HYDE. SAFETY COLLAR 'FOR ABRASIVE WHEELS.

APPLICATION FILED JUNE 6.1907.

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DAVID B. HYDE, OF SANTA ANA, CALIFORNIA.

SAFETY-COLLAR FOR ABRASIVE-WHEELS.

Speccaton of Letters Patent.

Patented Jan. 7, 1908.

Application filed June 1907. Serial No. 377.644.

To all whom it may concern:

Be it known that I, DAVID B. HYDE, a citizen of the United States, residing at Santa Ana, in the county of Orange and State of California, have invented a new and useful Improved Safety-Collar for Abrasive Wheels, of which the following is a specification.

An object of this invention is to prevent emery or other abrasive or grinding wheels from being broken by unequal side strain arising from the pressure of the clamping devices which hold the wheel on the arbor.

Another object of the invention is to safeguard the wheel in case of breakage, by preventing the broken pieces of wheel from flying and injuring the workmen should thel wheel be broken.

In the application of this invention it is preferable to make one or both sides of the wheel convex, or thicker at the eye of the wheel than at the periphery, and to make the elan'iping collars correspon(lingly concave or dished shape, and the invention is hereinafter described as embodied in connection with such a wheel.

In the accompanying drawingsI-Figure 1 is a longitudinal section of a wheel and the. clamping devices therefor. Fig. 2 is a side elevation of the wheel, the arbor being in section on the line Fig. 1. Figs. 3 and 4 are longitudinal sections showing other embodiments of the invention.

Referring to Figs. 1 and 2, 1 designates the emery or other abrasive grinding or polishing wheel, made convex on each side. 2 is a spindle therefor, the emery wheel preferably having an eye or bushing 3 fitting on or surrounding the spindle. e designates the fast collar on the spindle or arbor. 5 designates the loose collar thereon and 6 the clamping nut. Between the said collars and the collars 4 and 5 and the emery wheel are provided the clamping plates 7 which are centrally bored to receive the spindle or arbor. The bore or central opening 8 of these collars or clamping plates 7 is so formed, relativelyT to the. spindle or arbor 2, as to closely fit the latter at only a limited longitudinal portion thereof, or substantially in a single plane transverse to the spindle, thus, as shown in Fig. 1 the bore or opening 8 of the plateV 'fits closely or snugly on the arbor at the line indicated at 9, intermediate between the ends of the bore, and said bore diverges in each direction from this portion, so that in other portions of the bore the clamping plate is free from contact with the spindle. rllhe clamping plate is thus held and accurately centered in position with relation to the spindle by its limited longitudinal bearing thereon, but is -free to tip to a limited extent in any direction, and thus to adjust itself to the inequalities of the wheel.

In the forni of the invention shown in Fig. 3 the construction is the same except that the clamping plates, indicated at 10, have their point of smallest bore at the inner end or face as shown at 11, the bore diverging outwardly therefrom so that the plates contact with the shaft only at the inner ends of the bore.

Fig. 4f shows a reverse Vllare or divergence of the bore, namely, toward the inner face of the plates 12, this 'figure also showing the application of the invention to a wheel which is convex on only one side.

.In the manufacture of einery or abrasive wheels it has been found in practice that on account of the hard nature of the material wheels are made from, and on account of the hard nature of the bond used to cement the abrasive n'iaterial together, it is almost an impossibility to true the wheels up on their sides so they will be absolutely true to a given contour, or to the inner faces of the clamping devices. To remedy this defect, manufacturers have used pads of papel' or other yielding substances to, in a measure, compensate :for the inequalities of side surfaces.

In the using of large wheels clamping plates of large diameter and thickness have to be used in order to hold the broken pieces from flying from the collar and injuring the workmen, should a wheel from any cause become broken while in use. It is also necessary that the holes in the collars and the holes in the wheels should be as near the exact size of the spindle they are run on as possible, otherwise they would run so much out of balance that it would be impossible to use them. If the clamping plates lit the arbor snugly and a wheel is clamped between these plates that are not true one side relatively to the other, then when these plates are forced up against the sides, either the arbor is sprung, or the wheel is so badly strained, even though there are paper or other yielding pads used, that the wheel is unable to withstand the com bined centrifugal force and the unequal side pressure, the result being that the wheel breaks without any apparent reason. Many Wheels have been broken at a-speed at not over half the number of revolutions they had formerly been tested at, said tests being made on testing machines Without safety collar or clamp.

The construction above described with clamping plates bearing on the shaft only at a limited longitudinal portion avoids the above mentioned difhculty byvallowing the plates to adjust themselves to any slight inequalities in the Wheel faces Without straining either the Wheel or the arbor.

What l claim is l. A safety clamping plate for use in abrasive or polishing Wheels having a bore formed to give a bearing for the arbor Which is of limited longitudinal extent, the bore being enlarged at other portions to enable a limited tip of the plate on the arbor.

2. A safety clamping plate for use in connection with abrasive or polishing Wheels having a bore with a bearing portion for fitting the arbor, the remainder of said bore flaring from said bearing portion.

3. The combination With a convex sided abrasive Wheel and its arbor, of a clamping plate dished to it the side of the abrasive Wheel and having a bore fitting the arbor at a limited longitudinal portion thereof, said bore flaring from such arbor fitting portion, and means for clamping the plate against the Wheel.V

In testimony whereof, I have hereunto set my hand at Los Angeles California this 24th day of May 1907.

DAVID B. HYDE.

In presence of- ARTHUR l). KNIGHT, FRANK L. A. GRAHAM. 

